JP2001230242A - Plasma cvd device and its gas supply nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a gas supply nozzle generating less foreign matter when forming a film. SOLUTION: The gas supply nozzle 9 for introducing a film forming gas has an outer tube 23 and an inner tube 30. The tubes 23 and 30 have flanges at one ends. A plate 26 having low thermal conductivity is sandwiched between the flanges of the tubes 23 and 30, and the tubes 23, 30 and the plate 26 are mounted at the flange at a lower chamber 3 by bolts 27. Even when the tube 23 becomes a high temperature by colliding ions or the like to the outer surface of the tube 23 by sandwiching the plate 26, a temperature rise of the tube 30 can be prevented. An Ar gas flows to an air gap between the tubes 30 and 23, a pressure of the gap shows a low level from several value to 1,000 Pa, and the temperature rise of the tube 30 due to the thermal conduction is suppressed. As a result, since a temperature rise of SiH4 flowing in the tube 30 is low, and hence a reaction by-product due to the thermally decomposing reaction is not deposited in the tube 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a plasma CVD.
(Chemical vapor deposition
n) devices, especially microwave plasma and R
The present invention relates to a high-density plasma CVD apparatus having a cleaning function of forming a film using F (radio frequency) plasma and removing wall deposits in a reaction chamber.

[0002]

2. Description of the Related Art A plasma CVD apparatus is used for growing a thin film on a silicon wafer or another substrate.
In the process of growing a thin film on the surface of a substrate such as a silicon wafer using this plasma CVD apparatus, the thin film also grows on the inner wall surface of the reaction chamber other than the substrate and the inner and outer wall surfaces of the gas nozzle. This thin film is made of a type of film (SiO _{2 ,} Si ₃ N _{4 ,} pol
Although it varies depending on y-Si or the like, when the film is deposited to a certain thickness (several to several tens of μm), the film is cracked due to internal stress of the film itself and peels off from the wall surface.

[0003] The degree of the peeling greatly varies depending on the shape of the wall surface on which the film is deposited, the surface treatment, and the material. When the peeled matter generated by such a phenomenon adheres to the wafer surface, it becomes a foreign substance, causing disconnection or short circuit of the semiconductor circuit, which is a major cause of manufacturing defects.

As described above, foreign matter (particles) generated in a semiconductor manufacturing apparatus is a major factor that lowers the yield and the operating rate of the apparatus.

[0005] Therefore, before the phenomenon that the peeled material adheres to the wafer surface occurs, the deposited film deposited on the inner wall surface of the reaction chamber and the inner and outer wall surfaces of the gas nozzle must be removed.

[0006]

By the way, for example, in a plasma CVD apparatus for forming an insulating oxide film (SiO ₂ ), in order to ensure uniformity of the film thickness on the substrate, a source gas of SiH ₄ gas is used. Is introduced into the reaction chamber by a plurality of tubular gas nozzles.

In such a structure, a large number of ions and electrons collide with the gas nozzle surface, so that the gas nozzle temperature rises. The highly reactive Si
When H ₄ gas or the like flows, the gas temperature rises, causing a thermal decomposition reaction in the nozzle, and a reaction by-product such as polysilicon (Poly-Si) is generated and deposited on the inner wall surface of the nozzle.

The deposit on the inner wall surface of the nozzle may peel off and adhere to the wafer surface. In order to prevent this, the reaction by-products accumulated in the nozzles must be periodically removed by dry cleaning using NF ₃ gas or the like. For this reason, there is a problem that the throughput of the device is reduced.

As a known example related to the reduction of foreign matter from a gas nozzle, there is Japanese Patent Application Laid-Open No. 11-87249. In this known example, in order to prevent a reaction product attached to the side of a cylindrical gas nozzle having a closed upper surface from peeling and attaching to a wafer, a gas ejection port on the side of the gas nozzle is protruded to separate from the nozzle. Foreign matter is received at this part.

However, the method according to the known example has a problem that the foreign matter once received falls and adheres to the wafer.

Therefore, there is still a problem that the reactive gas is heated while flowing through the gas nozzle to cause a thermal decomposition reaction, a reaction by-product is deposited in the nozzle, and this deposit is peeled off to become a foreign substance. was there.

The present invention has been made in order to avoid the above problems, and an object of the present invention is to prevent foreign matter from being generated during film formation.
An object of the present invention is to realize a gas supply nozzle and a plasma CVD apparatus having a high operation rate using the same.

[0013]

In order to achieve the above object, the present invention is configured as follows. (1) In a plasma CVD apparatus for introducing a gas into a reaction chamber to generate microwave plasma and RF plasma, and forming a thin film on a wafer or the like installed on a substrate electrode,
A film forming gas is introduced into a reaction chamber from a gas supply nozzle having a double pipe structure including a cylindrical inner pipe and an outer pipe.

(2) Preferably, in the above (1),
The reactive gas of the above-mentioned film forming gas is caused to flow through the inner tube of the gas supply nozzle having a double tube structure, and another film forming gas other than the reactive gas is caused to flow through the outer tube.

(3) Preferably, in (2) above, the gas outlet of the inner tube is recessed from the gas outlet of the outer tube of the gas supply nozzle having the double tube structure.

(4) A gas supply nozzle of a plasma CVD apparatus for introducing a gas into a reaction chamber to generate microwave plasma and RF plasma to form a thin film on a wafer or the like provided on a substrate electrode. The cladding tube is covered so as to form a minute gap on the outside, and is connected to the reaction chamber wall surface so that heat can easily escape.

(5) Preferably, in the above (4), the cladding tube is a cladding tube made of a material having a high thermal conductivity such as Al and AlN.

(6) Preferably, the above (4),
In (5), a throttle is provided on the gas outlet side of the tubular nozzle.

(7) a polysilicon film for the gate electrode wiring,
In a semiconductor device provided with at least one of a phosphorus-doped polysilicon film, an oxide film or a phosphorus glass film for interlayer insulation, and a Si ₃ N ₄ film for capacitor insulation, at least one of the above-mentioned films is (1) The film is formed using the plasma CVD apparatus of (3) to (3).

(8) A gas is introduced into the reaction chamber to generate microwave plasma and RF plasma, and a gas supply nozzle of a plasma CVD apparatus for forming a thin film on a wafer or the like provided on a substrate electrode is used to form a cylindrical gas. It has a double pipe structure consisting of an inner pipe and an outer pipe.

(9) Preferably, in the above (8),
The gas outlet of the inner pipe is recessed from the gas outlet of the outer pipe of the gas nozzle having the double pipe structure.

(10) Preferably, the above (1),
In (2) and (3), the material of the gas supply nozzle is Al ₂ O ₃ .

The temperature of the inner tube is increased by ion bombardment or the like by introducing the film forming gas into the reaction chamber by using a gas supply nozzle having a double tube structure comprising a plurality of cylindrical inner tubes and outer tubes. Suppress.

The inner pipe of the gas supply nozzle having a double pipe structure has Si
By flowing a reactive gas such as H ₄ or a gas such as Ar or O ₂ (a deposition gas other than the reactive gas) into the outer tube, a rise in the temperature of the inner tube due to ion bombardment or the like is suppressed.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) A plasma CVD apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 3 are longitudinal sectional views showing the shape of the longitudinal section of the reaction chamber 1,
FIG. 2 is an explanatory diagram showing a flow of processing in the first embodiment, and FIG. 4 is a detailed structural diagram of a gas nozzle unit in the first embodiment.

The overall configuration of the apparatus will be described with reference to FIG.

The reaction chamber 1 includes an upper chamber 2 made of an Al alloy.
And the lower chamber 3. The upper chamber 2 and the lower chamber 3 are insulated from each other by an insulating material 6.
The upper chamber 2 is provided with a plurality of gas nozzles 4 made of alumina (Al ₂ O ₃ ) or the like for introducing a film-forming gas such as O _{2, and a} microwave introduction window for introducing a microwave. 5 (made of quartz, etc.) are provided at several places.

A waveguide 18 for guiding a microwave is connected to the microwave introduction window 5. Further, a μ-wave oscillator 19 (frequency 2.45) for generating a μ-wave is provided at the end of the waveguide 18.
GHz), and a microwave power supply 21 is attached.

Further, a matching box 7 and an RF power supply 8 (frequency 13.56 MHz) are connected to the wall surface of the upper chamber 2 so that RF power can be applied. An ECR (Electron Cyclotron Resonance) region is formed on the outer surface of the upper chamber 2 near the exit of the microwave introduction window 5 to increase electron density, promote generation of ions and radicals, and generate high density plasma. A plurality of permanent magnets 20 for forming a cusp magnetic field are provided for performing the operation and confining the plasma generated in the reaction chamber 1.

A plurality of gas nozzles 9 made of alumina (Al ₂ O ₃ ) or the like for introducing a film forming gas such as SiH ₄ or Ar are provided in the lower chamber 3 in the circumferential direction. A pump 10 is mounted. Further, a roughing vacuum pump 11 such as a positive displacement pump and a gas processing device 12 are connected to the tip of the turbo molecular pump 10. Also,
The lower chamber 3 is grounded.

In the reaction chamber 1, a wafer 13 for a film forming process is provided.
A substrate electrode 15 incorporating an electrostatic attraction device 14 for adsorbing is installed. A matching box 16 and an RF power supply 17 are connected to the substrate electrode 15 so that RF power can be applied.

The wafer 13 is heated not only by the heat input from the plasma but also by the incidence of ions and the heat of reaction.
Since the temperature of the wafer 13 has a great influence on the film quality, the film formation rate, etc., it is necessary to control the temperature of the wafer 13. This control is performed by the pressure of the helium (He) gas flowing in the gap between the wafer 13 and the electrostatic chuck 14.

Next, the detailed structure of the gas nozzle 9 according to the first embodiment of the present invention will be described with reference to FIG. The gas supply nozzle 9 has an outer tube 23 and an inner tube 30. The outer tube 23 and the inner tube 30 each have a flange at one end, and the outer tube 23
A plate 26 of low thermal conductivity such as SiO ₂ is sandwiched between the flange of the inner tube 30 and the flange of the inner tube 30, and the outer tube 23, the inner tube 30, and the plate 26
Is attached to the lower chamber 3 at the flange portion from the atmosphere side. By sandwiching the plate 26, the outer tube 2
Even when ions or the like collide with the outer surface of the outer tube 3 and the outer tube 23 becomes hot, the temperature of the inner tube 30 can be prevented from rising.

An O-ring 24 is inserted into an O-ring groove 25 provided in the outer tube 23, the inner tube 30, and the lower chamber 3. Thereby, the reaction chamber side and the atmosphere side, the gas introduction pipe 2
8 and the gas introduced from the gas introduction pipe 29 are not mixed. In addition, the gas introduction pipe 28 includes the inner pipe 30 and the outer pipe 2.
8 for introducing a gas (Ar gas, which is another film forming gas other than the reactive gas among the film forming gases). This is for introducing a reactive gas SiH ₄ ) among the film gases.

FIG. 2 is an explanatory diagram showing the flow of processing in the plasma CVD apparatus according to the first embodiment. As shown in FIG. 2, the processing is sequentially repeated after a plurality of wafer film forming processes → cleaning → precoat → film forming → cleaning.

When the film forming process is repeated a plurality of times, a film of a reaction by-product is gradually deposited on the inner wall surface of the reaction chamber 1 and the surface of the substrate electrode 15. When the deposit exceeds a certain thickness, a crack is generated in the deposited film due to the internal stress of the film itself. In the worst case, the crack is peeled off from the wall surface and adheres to the surface of the wafer 13, and the semiconductor element wiring Causes short-circuiting or disconnection, resulting in defective manufacturing and lowering production efficiency.

Therefore, before such a phenomenon occurs,
Cleaning for removing the deposited film in the reaction chamber 1 is performed, and subsequently, pre-coating for preventing the occurrence of foreign substances due to cleaning is performed. Hereinafter, each specific method will be described.

(1) Film Forming Method A film forming method using the above-described apparatus will be described with reference to FIGS. First, the wafer 13 is introduced into the reaction chamber 1 whose pressure has been adjusted by the turbo molecular pump 10 and the roughing vacuum pump 11 via the transfer chamber (not shown), and is placed on the substrate electrode 15. By applying a voltage to the electrostatic attraction device 14, the wafer 13 is attracted by electrostatic force.

In this state, for example, oxygen gas is supplied from the gas nozzle 4, Ar gas is supplied from the gas introduction pipe 28 of the gas nozzle 9, and SiH ₄ gas is supplied from the gas introduction pipe 29 to the reaction chamber 1 by a desired amount using a mass flow controller. Introduce. Then, the pressure in the reaction chamber 1 is adjusted from several millimeters to several tens Pa using the turbo molecular pump 10 and the roughing vacuum pump 11.

As described above, when a few hundred to several Kw μ-waves are introduced from the μ-wave introduction window 5, a large amount of electrons generated in the ECR region turn O ₂ , Ar, and SiH ₄ into plasma, thereby generating The SiH ₃ , which is a decomposition product of the obtained SiH ₄ , reacts with oxygen or the like on the surface of the wafer 13, whereby an SiO ₂ film is deposited on the wafer 13.

At the same time, the RF power source 1 is connected to the substrate electrode 15.
7 and the matching box 16 to make several hundred to several K
When an RF power of w is applied, a plasma sheath is formed between the surface of the wafer 13 and the plasma, and a bias voltage (−several tens to thousands of volts) is generated. Ar) is incident on the surface of the wafer 13 by the electric field. Thus, the SiO ₂ film deposited on the surface of the wafer 13 is sputtered with Ar ions.

By doing so, an SiO ₂ film can be formed on a step portion such as an Al wiring without voids (voids). After depositing a desired film thickness, stopping the gas introduction, the application of microwaves, and the application of RF, the applied voltage to the electrostatic suction device 14 is turned off.
Then, the wafer 13 is carried out of the reaction chamber 1.

During the film formation, a large amount of ions collide with the outer surface of the outer tube 23 of the gas nozzle 9, so that the temperature of the outer tube 23 rises. However, in the first embodiment of the present invention, Ar gas flows in the gap between the inner pipe 30 and the outer pipe 23, and the pressure in this gap is as low as several to 1000 Pa. Temperature rise can be suppressed.

Further, since the plate 26 made of SiO ₂ or the like having low thermal conductivity is sandwiched between the inner tube 30 and the outer tube 23,
The temperature rise of the inner tube 30 due to direct heat conduction from the outer tube 23 is small. As a result, the temperature rise of SiH ₄ flowing in the inner tube 30 is reduced, so that reaction by-products due to the thermal decomposition reaction do not deposit on the inner wall surface of the inner tube 30.

As a result, dust generation from the gas nozzle 9 during film formation can be prevented.
There is an effect that a VD device can be realized.

(2) Cleaning Method Next, a cleaning method will be described with reference to FIG. First, via a transfer chamber (not shown), alumina is used to protect the surface of the electrostatic adsorption device 14 from plasma in the reaction chamber 1 whose pressure is adjusted by the turbo-molecular pump 10 and the roughing vacuum pump 11. The cover wafer 22 is introduced and placed on the substrate electrode 15.

In this way, a desired amount of NF ₃ gas is introduced from the gas nozzle 4 into the reaction chamber 1 by using a mass flow controller, and several to several thousand Pa is applied by using a turbo molecular pump 10 and a roughing vacuum pump 11. In addition to adjusting the pressure in the reaction chamber 1, the RF power of several hundreds to several kW is applied to the upper chamber 2 using the RF power supply 8 and the matching box 7.

As a result, NF ₃ plasma is generated in the reaction chamber 1. F radical generated by decomposition of NF ₃ gas,
The F ions react with Si of the SiO ₂ film and are discharged as a gas such as SiF ₄ to clean (etch) the deposited film on the wall surface.

(3) Pre-coating method The reaction by-product deposited on the wall surface of the reaction chamber 1 as described above is removed. At this time, since the deposition distribution of the reaction by-product is different from the etching distribution of the deposited film by the cleaning, if the entire deposit on the wall of the reaction chamber is removed, the wall itself is etched in the portion where the film was removed in the initial stage. That is, over-etching occurs.

Therefore, in the film formation immediately after the completion of the cleaning, the reaction chamber 1 has a rough inner wall surface, and a reaction product or gas adsorption by the cleaning remains on the inner wall surface.

Further, since the conductive wall surface is exposed immediately after the cleaning, a large amount of electrons generated by the plasma are accumulated in the insulating film on the wall surface of the reaction chamber 1 and the gap between the conductive wall surface and the insulating film becomes large. The dielectric breakdown of the deposited film is caused by the potential difference, and foreign matter frequently occurs.

To prevent these problems, the inner wall surface of the reaction chamber 1 is pre-coated immediately after cleaning. The precoating method will be described with reference to FIG. First, the wafer 13 is introduced into the reaction chamber 1 whose pressure has been adjusted by the turbo molecular pump 10 and the roughing vacuum pump 11 via the transfer chamber (not shown), and is placed on the substrate electrode 15. By applying a voltage to the electrostatic attraction device 14, the wafer 13 is attracted by electrostatic force.

In this state, for example, oxygen gas from the gas nozzle 4 and Ar and SiH ₄ gas from the gas nozzle 9 are introduced into the reaction chamber 1 in desired amounts by using a mass flow controller, and a turbo molecular pump 10 and a roughing vacuum pump 11 are introduced. Is used to adjust the pressure in the reaction chamber 1 to several millimeters to several tens Pa.

In this way, when a μ-wave of several hundreds to several kW is introduced from the μ-wave introduction window 5, a large number of electrons generated in the ECR region turn O ₂ , Ar, and SiH ₄ into plasma, thereby generating By reacting SiH ₃ , which is a decomposition product of the SiH ₄ , with oxygen and the like, an SiO ₂ film is deposited on the inner wall surface of the reaction chamber 1. After the desired film thickness is deposited, the gas introduction and the application of the microwave are stopped, and the voltage applied to the electrostatic attraction device 14 is reduced to O.
The FF is carried out of the reaction chamber 1.

Also in this precoating, since dust generation from the gas nozzle 9 can be prevented as in the case of film formation, there is an effect that a plasma CVD apparatus with less generation of foreign substances can be realized.

That is, according to the first embodiment of the present invention, it is possible to realize a gas supply nozzle and a plasma CVD apparatus having a high operation rate using the gas supply nozzle, which hardly generate foreign matter during film formation.

(Second Embodiment) The structure of a gas nozzle 9 according to a second embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 3 is a cross-sectional view showing a structure for attaching the gas nozzle 9 to the chamber 3. The basic structure of the second embodiment is the same as the gas nozzle 9 of the first embodiment shown in FIG. The differences between the first embodiment and the second embodiment are as follows.
The gas outlet (tip) of the inner tube 30 is recessed from the gas outlet of the inner tube 23.

With this structure, the gas introduction pipe 2 of the gas nozzle 9
Ar gas is introduced into the reaction chamber 1 through the gas introduction pipe 29, and SiH ₄ gas is introduced into the reaction chamber 1 from the gas introduction pipe 29 using a mass flow controller. During the film formation, a large amount of ions collide with the outer surface of the outer tube 23 of the gas nozzle 9, so that the temperature of the outer tube 23 rises.

However, in the second embodiment of the present invention, Ar gas flows through the gap between the inner pipe 30 and the outer pipe 23;
Further, since the pressure in the gap is as low as about several Pa to 1000 Pa, it is possible to suppress a rise in the temperature of the inner tube 30 due to heat conduction. Further, since the plate 26 made of SiO ₂ or the like having low thermal conductivity is sandwiched between the inner tube 30 and the outer tube 23, the temperature rise of the inner tube 30 due to direct heat conduction from the outer tube 23 is small.

As a result, the temperature rise of SiH ₄ flowing in the inner tube 30 is reduced, so that by-products of the thermal decomposition reaction do not accumulate on the inner wall surface of the inner tube 30.

Further, the gas outlet (tip) of the inner tube 30 is
Since the gas is recessed (about several mm) from the gas outlet of the inner tube 23, the Ar gas wraps around the SiH ₄ gas.
It is supplied into the reaction chamber 1.

As a result, it is possible to prevent the accumulation of reaction by-products not only on the inner wall surfaces of the inner tube 30 and the outer tube 23 but also on the surface near the outlet of the inner tube 30. Because of these, dust generation from the gas nozzle 9 during film formation can be prevented, so that a gas supply nozzle with less generation of foreign matter and a plasma CV using the same are provided.
There is an effect that the D device can be realized.

Plasma CVD using this gas nozzle 9
The film forming method, pre-coating method, and overall processing flow in the apparatus are the same as in the first embodiment. That is, plasma CVD
The configuration of the device is the same as that of the first embodiment.

(Third Embodiment) The structure of a gas nozzle 9 according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a sectional view showing a structure for attaching the gas nozzle 9 to the chamber 3. In FIG. 6, in the third embodiment, the lower chamber 3 is divided into upper and lower parts 3-A and 3-B, and a gas groove 37 is provided over the entire circumference of the lower chamber 3-A. The gas supply pipe 33 is connected to the gas groove 37. The lower chambers 3-A and 3-B are provided with a plurality of bolts 34 by inserting an O-ring 35 into an O-ring groove 36 of the lower chamber 3-B.
Assembled with

A screw hole 38 is provided in the lower chamber 3-A so as to penetrate the gas groove 37. The inner tube 32 made of, for example, Al ₂ O ₃ is attached to the lower chamber 3-A using the screw holes 38. Further, an outer tube (cladding tube) 31 having good heat conductivity, such as Al or AlN, having an inner diameter larger than the outer diameter of the inner tube 32 is attached to the lower chamber 3-A using a screw hole 39.

With this structure, the gas introduction pipe 3 of the gas nozzle 9
From step 3, a desired amount of a mixed gas of Ar and SiH ₄ is introduced into the reaction chamber 1 using a mass flow controller to form a film. During film formation, a large amount of ions collide with the outer surface of the outer tube 31 of the gas nozzle 9, so that the temperature of the outer tube 31 increases.

However, in the third embodiment of the present invention, the material of the outer tube 31 is Al or AlN having good heat conductivity, and
The outer tube 31 is screwed to the lower chamber 3-A made of aluminum. Therefore, the heat of the outer tube 31 easily escapes to the lower chamber 3-A.

The pressure in the gap between the inner tube 32 and the outer tube 31 is about several Pa, which is close to the pressure in the reaction chamber 1.
The temperature rise of the inner tube 32 due to heat conduction is reduced.

As a result, the temperature rise of the SiH ₄ flowing in the inner tube 32 is reduced, and the reaction by-products due to the thermal decomposition reaction do not deposit on the inner wall surface of the inner tube 32. And plasma C using the same
There is an effect that a VD device can be realized.

Plasma CVD using this gas nozzle 9
The film forming method, pre-coating method, and overall processing flow in the apparatus are the same as those in the first embodiment. That is, the plasma CV
The configuration of the D device is the same as in the first embodiment.

(Fourth Embodiment) The structure of a gas nozzle 9 according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a sectional view showing a structure for attaching the gas nozzle 9 to the chamber 3. In FIG. 7, the basic structure of the gas nozzle 9 of the fourth embodiment is the same as that of the gas nozzle 9 of the third embodiment. The difference between the third embodiment and the fourth embodiment is that the gas nozzle 9 of the fourth embodiment is provided with a throttle at the gas outlet of the inner tube 40.

With this structure, the gas inlet pipe 3 of the gas nozzle 9
From step 3, a desired amount of a mixed gas of Ar and SiH ₄ is introduced into the reaction chamber 1 using a mass flow controller to form a film. During film formation, a large amount of ions collide with the outer surface of the outer tube 31 of the gas nozzle 9, so that the temperature of the outer tube 31 increases.

However, in the fourth embodiment of the present invention, the material of the outer tube 31 is Al or AlN having good heat conductivity, and
The outer tube 31 is screwed to the lower chamber 3-A made of aluminum. Therefore, the heat of the outer tube 31 easily escapes to the lower chamber 3-A.

Since the pressure in the gap between the inner tube 40 and the outer tube 31 is about several Pa which is close to the pressure in the reaction chamber 1, the temperature rise of the inner tube 32 due to heat conduction is reduced. As a result, the temperature rise of SiH ₄ flowing in the inner tube 32 is reduced, so that reaction by-products due to the thermal decomposition reaction do not accumulate on the inner wall surface of the inner tube 32.

Further, since the gas outlet of the inner pipe 40 is provided with a throttle, the flow velocity of the gas outlet is increased, and the reaction at the gas outlet is suppressed.

[0086] These effects have the effect of realizing a gas supply nozzle with less generation of foreign matter and a plasma CVD apparatus using the same.

Plasma CVD using this gas nozzle 9
The film forming method, pre-coating method, and overall processing flow in the apparatus are the same as in the first embodiment. That is, plasma CVD
The configuration of the device is the same as that of the first embodiment.

The semiconductor device which can be plasma-processed by using the plasma CVD apparatus using the gas nozzle according to the above-described embodiment includes a polysilicon film for a gate electrode wiring, a phosphorus-doped polysilicon film, and an oxide film for interlayer insulation. Film or phosphor glass film, S for capacitor insulation
A semiconductor element provided with at least one film among the i ₃ N ₄ films is given.

[0079]

According to the present invention, the gas nozzle for film formation has a double pipe structure composed of an inner pipe and an outer pipe, and the gas for film formation is introduced by the inner pipe. A gas supply nozzle capable of reducing the accumulation of reaction by-products due to a thermal decomposition reaction on the inner surface of a gas nozzle for introducing a raw material gas into a room and preventing the generation of foreign substances from the inner surface of the gas nozzle during film formation, and an operation rate using the gas supply nozzle Therefore, there is an effect that a plasma CVD apparatus having a high density can be realized.

[Brief description of the drawings]

FIG. 1 shows a plasma CV according to a first embodiment of the present invention.
It is a reaction chamber side sectional view at the time of the film-forming process of D device.

FIG. 2 is a plasma CV according to the first embodiment of the present invention.
FIG. 9 is an explanatory diagram showing a flow of processing of the D device.

FIG. 3 is a sectional view on the reaction chamber side during cleaning of the plasma CVD apparatus of the first embodiment.

FIG. 4 is a detailed structural view of a gas nozzle unit according to the first embodiment.

FIG. 5 is a detailed structural view of a gas nozzle unit according to a second embodiment.

FIG. 6 is a detailed structural view of a gas nozzle unit according to a third embodiment.

FIG. 7 is a detailed structural view of a gas nozzle unit according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction chamber 2 Upper chamber 3 Lower chamber 3-A, 3-B Lower chamber 4 Gas nozzle 5 Microwave introduction window 6 Insulation material 7 Matching box 8, 17 RF power supply 9 Gas supply nozzle 10 Turbo molecular pump 11 Roughing pump 12 Gas Processing device 13 Wafer 14 Electrostatic attraction device 15 Substrate electrode 16 Matching box 18 Waveguide 19 Microwave oscillator 20 Permanent magnet 21 Microwave power supply 22 Cover wafer 23, 31 Outer tube 24, 35 O-ring 25, 36 O-ring groove 26 Plate 27, 34 Bolt 28 Gas inlet tube 29, 33 Gas inlet tube 30, 32 Inner tube 40 Inner tube 37 Gas groove 38, 39 Screw hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Hachiya 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside Kokubu Works, Hitachi, Ltd. (72) Katsumi Oyama 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture No. 1 F-term in Kokubu Office of Hitachi, Ltd. (reference) 4K030 AA06 AA16 BA29 BA40 BA42 BA44 BA61 DA06 EA05 FA01 FA02 KA46 LA15 5F045 AA08 AA09 AB03 AB32 AB33 AB35 AC01 AC11 AC16 AC17 DP04 EF01 EF11 EH13 EH17EJ10

Claims (10)

[Claims] 1. A plasma CVD apparatus for generating a microwave plasma and an RF plasma by introducing a gas into a reaction chamber to form a thin film on a wafer or the like installed on a substrate electrode. A plasma CVD apparatus characterized in that a film forming gas is introduced into a reaction chamber from a gas supply nozzle having a double pipe structure comprising: 2. The plasma CVD apparatus according to claim 1, wherein a reactive gas of the film forming gas flows through the inner pipe of the gas supply nozzle having a double pipe structure, and the other gas other than the reactive gas flows into the outer pipe. Plasma C characterized by flowing a film forming gas of
VD device. 3. The plasma CVD apparatus according to claim 2, wherein the gas outlet of the inner tube is recessed from the gas outlet of the outer tube of the gas supply nozzle having a double tube structure. . 4. A gas supply nozzle of a plasma CVD apparatus for generating a microwave plasma and an RF plasma by introducing a gas into a reaction chamber to form a thin film on a wafer or the like provided on a substrate electrode. A gas supply nozzle for a plasma CVD apparatus, wherein the gas supply nozzle is covered with a coating tube so as to form a minute gap and is connected to a reaction chamber wall so that heat can easily escape. 5. The gas supply nozzle of a plasma CVD apparatus according to claim 4, wherein said cladding tube is a cladding tube made of a material having a high thermal conductivity such as Al or AlN. Feed nozzle. 6. The gas supply nozzle according to claim 4, wherein a throttle is provided on the gas outlet side of the tubular nozzle. 7. A semiconductor having at least one of a polysilicon film for a gate electrode wiring, a phosphorus-doped polysilicon film, an oxide film or a phosphorus glass film for interlayer insulation, and a Si ₃ N ₄ film for capacitor insulation. A semiconductor device, wherein at least one of the films is formed using the plasma CVD apparatus according to any one of claims 1 to 3. 8. A gas supply nozzle of a plasma CVD apparatus for introducing a gas into a reaction chamber to generate microwave plasma and RF plasma to form a thin film on a wafer or the like provided on a substrate electrode. A gas supply nozzle for a plasma CVD apparatus, having a double tube structure comprising a tube and an outer tube. 9. A gas supply nozzle for a plasma CVD apparatus according to claim 8, wherein the gas outlet of the inner tube is recessed from the gas outlet of the outer tube of the gas nozzle having the double tube structure. Gas supply nozzle for CVD equipment. 10. The plasma CVD apparatus according to claim 1, wherein the material of the gas supply nozzle is Al ₂ O ₃ .